William h



(No Model.)

W. H. D0LM'AN. FIRE PROQPT-IMBEB;

,721. Patented Pb, 19, 1884.

INVENTOR:

WITNESSES:

ATTORNEY-S:

N4 PETERS. mwumu m m. Washington. a. c.

' UNITED STATES PATENT OFFICE.

' WILLIAM H. DOLMAN,

OF NEW YORK, N. Y.

FIRE-PROOF TIMBER...

SPECIFICATION forming part of Letters Patent No. 293,721, dated February 19, 1884.

Application filed September 26, 1883. (No model.)

f2" 0 all whom it may concern:

Be it known that I, WILLIAM H. DOLMAN, of the city, county, and State of New York, have invented certain new and useful Improvements in FireProof Timbers, of which the following is' a full, -clear,and exact description.

The object of the invention is to form convenient pockets or chambers for holding nonconducting material around building and other timbers. I

Reference is to be had to the accompanying drawings, forming part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure l is'a broken perspective View, showing my invention applied to the posts and joists of a gallery. Fig. 2 is a perspective View, enlarged, showing the method of surrounding the timber with ashes and metal; and Figs. 3 andet show modifications.

In carrying my invention into effect, the timher A is first made ready for use with the allowance for increasing its size on each side of from one inch and a half to three inches. I then nail on the timber A the narrow strips a a of the required thickness, and about one foot apart. To these strips a a, I nail the iron sheets B B, and fill the space between them and the timber A with dry sifted ashes, earth, or other non-conducting material, asshown at b I), care being taken that no openings are left in the plates of iron through which the non-conducting material could sift.

For posts, as at 0, Fig. 1, round, instead of square, timbers might be used, in which case the outer casing of iron would be made tubular and cast, or rolled from sheet-iron, and the casing might be ornamented in relief or otherwise, to suit the taste, if desired.

For rafters or joists, as at D, Fig. 1, in most cases the timber wil be square, and the nonconducting Inateria and iron casing will be applied as above described; but instead of using four separate plates, as mentioned, the sheets of metal might be bent into trough form, as shown at d, Fig. 3, to be used with one covering-plate, d, as indicated in said-figure; or

two plates bent to form right angles, as shown 'atf f, Fig. 4, might be used for incasing the square timbers.

Protected in the manner described'by the iron and non-conducting material, the timbers will stand an intense heat without burning and they are cheaper than all-iron posts, rafters, beams, &c., and will not bend under weight, as iron is liable to do when subjected to great heat, as they would be in the event of the burning of the building.

Having thus described my invention, I claim asnew and desire to secure by Letters Patent- The combination, with a joist, rafter, or other piece of timber, of the narrow strips a and metallic sheets B, arranged to form pockets or chambers, and non'conducting material fill- I ing said spaces between the iron and the wood, as shown and described.

WILLIAM H. DOLMAN. Witnesses:

H. A. WEST, O. SEDGWIOK. 

